With smartphones and tablets having become widely deployed as well as 3G and Wi-Fi based access to Internet, data capture technologies work as an interface between databases and user devices. Example data capture technologies include bar codes, QR codes, Radio Frequency Identification (RFID) and Near Field Communication (NFC). Most of these technologies are used as either a visible or an invisible tag to connect these databases and user devices. The introduction of cloud storage adds extended use of data exchange between data storage and end user devices.
Many households include many different devices simultaneously connected to Wi-Fi access points. This ubiquitous Wi-Fi usage increases electromagnetic fields around the home environment. Despite the usefulness of Wi-Fi, long term consequences for the human body and general health are not clear.
End user devices such as smartphones and tablets are frequently equipped with photo and/or video cameras. These cameras can be used for capturing information presented in different visual forms. The other data capture technologies descried earlier, including bar codes and especially two dimensional (2D) bar codes such as QR codes, have attracted the attention of many researchers and companies due to the potential for inexpensive operation.
Bar codes have been used for mobile applications to deliver a multitude of different mobile services over mobile phones and other mobile communication or computing devices. Such applications range from providing Uniform Resource Locator (URL) information to link a mobile device to the Internet, through to using a bar code as a form of e-ticket for airlines or event admissions. Hence, there is an ever growing demand for higher capacity bar codes, suited for robust application on mobile devices. Traditional approaches to higher capacity bar codes include: (i) using a colored symbol set and (ii) increasing the size of the bar code. There are known limitations for either approach, especially related to mobile devices with compromised, low resolution cameras. The traditional data capacity of 1D and 2D bar codes is severely limited. This severely limited data capacity constrains possible applications of 1D and 2D bar codes, and their primary task is simply linking camera phones to designated Web sites. Additional tasks may then be performed based on the Web site. This operation again is based on using of Wi-Fi or 3G connectivity.
The maximum data capacity of 2D bar codes has been improving over the recent years, resulting in the introduction of newer applications.
Presently, the use of color-based bar code and other symbolic encoding in color space technologies using mobile devices such as camera mobile phones has been limited by the physical size of the actual bar code symbol in relation to the information encoded within, and also by the image capturing mechanism on mobile devices to discriminate or resolve effectively a greater multitude of colors, especially under varied lighting conditions by an inexperienced, lay user. Another limiting factor has been color fidelity of hard copy output devices, such as color printers, in reproducing the true colors of such color based bar code or symbol sets in a color space.
While bar codes can be used to provide 2D encoded data, they have not been used to provide real storage devices and media.